Food refluxing upwards into the mouth after meals may be caused by indigestion, reflux esophagitis, gastric ulcer and other diseases, and it is recommended to go to the hospital for examination in time. 1. Indigestion: It may be due to overfeeding, food cannot be digested in time in the stomach, resulting in excessive pressure in the stomach, which leads to the reflux of food upwards into the mouth. 2. Reflux esophagitis: due to the dysfunction of the lower esophageal sphincter, resulting in the reflux of food from the stomach, the gastric acid and bile refluxed into the esophagus damages the esophageal mucosa, leading to esophageal inflammation. 3. Gastric ulcer: Excessive drinking, smoking, irregular diet, irregular work and rest, etc. may trigger gastric ulcer, resulting in decreased digestive function and reflux of gastric contents. It is necessary to pay attention to the situation of food back up to the mouth after meals, to consult a doctor for treatment in a timely manner, to clarify the cause of the disease, and actively cooperate with the doctor’s treatment.